The receivers for Pike River Coal say any attempts to re-enter the West Coast mine are still some time away and it may not be possible to recover the bodies of those who died there last year.
Twenty-nine men were killed in a series of explosions in the West Coast mine that began on 19 November last year.
It was agreed on Monday that work would begin on making the mine airtight and to investigate a re-entry operation.
But the receiver for Pike River Coal, Malcolm Hollis, told Morning Report that it is still to be decided whether there will be a recovery of remains and who would fund it.
Mr Hollis said the plan to seal the entrance of the mine has always been under consideration and is part of the stabilisation plan.
He says the men's bodies are behind a rockfall at the top of the tunnel and getting there is "difficult, time-consuming and expensive." Receivers are working with the families but funding needs to be ascertained.
"What was agreed to was that parties would be involved in putting together feasibility studies around the various options that have been mooted for re-entering the main area of the mine," he said, adding that it was some time away.
Deal a milestone, say families
Mines Rescue is yet to confirm the plan, but a family spokesperson, Bernie Monk, says it is a significant step forward.
"We've been on this for months, and finally we've got there, and we've made significant steps."
The former safety manager at the mine also believes Monday's agreement is a major breakthrough.
Neville Rockhouse, whose son Ben died in the mine, told Morning Report that for the first time people are talking about a body recovery plan, rather than a mine recovery plan.
"All parties getting round the table and saying 'let's make this thing happen' is a milestone in itself."
Mine safety expert David Feikert says any recovery operation would be tough. Crews would have to make their way bit by bit along the tunnel, carrying breathing gear, always alert for any new rock fall.
His comments echo the views of the Mines Rescue Service made in a confidential memo obtained by Radio New Zealand two weeks ago.
The document spoke of a long journey into the mine, uphill, in hot, humid conditions, carrying heavy gear, with considerable difficulties in identifying the potential risks along the route.
The Engineering, Printing and Manufacturing Union says it believes a feasibility study into re-entering the Pike River Coal mine will reveal it is entirely possible.
Stabilisation work to begin
Up to 20 people, including the families' lawyers, the receivers for Pike River Coal, police and the Mines Rescue Service met in Christchurch on Monday to discuss the recovery.
It was agreed that work will begin next week to stabilise the air in the 2.3km tunnel that leads to the mine.
A lawyer for the families, Richard Raymond, says Mines Rescue staff will on Monday start building a temporary seal 100 metres inside the mine's opening, then put permanent double doors on the outside to stop any chance of another explosion.
After that, it is hoped recovery teams can advance in stages down the entry shaft before tunnelling around 50 metres of rockfall to reach any remains.
Assistant Police Commissioner Grant Nicholls says he has to take the discussions back to Wellington before he knows how much police can do.